I've covered below topics in current presentation: - Message Queue Introduction - Architecture - Key Capabilities - Simple Use Case - Difference between Web Service and Message Queue - ActiveMQ Portal I'll be adding one more presentation on MQ Testing through Parasoft SOATest. Please feel free to contact if you need more information.

1. Message Queue (MQ) Testing
UJJWAL GUPTA

2. Introduction: MESSAGE QUEUE (MQ)
 Message queuing allow applications to communicate by sending messages to each other. The
message queue provide a temporary message storage when the destination program is busy or not
connected.
 Message Queuing provides guaranteed message delivery, efficient routing, security, and priority-
based messaging.
“Message Queue provides an asynchronous communications protocol, a system that puts
a message onto a message queue does not require an immediate response to continue
processing”.
 Email is probably the best example of asynchronous messaging. When an email is sent can the sender
continue processing other things without an immediate response from the receiver. This way of
handling messages decouple the producer from the consumer. The producer and the consumer of the
message do not need to interact with the message queue at the same time.
 A Queue is a line of things waiting to be handled - in sequential order starting at the beginning of the
line. A message queue is a queue of messages sent between applications.
 A Message is the data transported between sender and receiver application, it's essentially a byte
array with some headers on top.

3. MQ Architecture
The Basic architecture of Message Queue is simple, there are client applications
called producers that create messages and deliver them to the message queue. An
other application, called consumer, connect to the queue and get the messages to
be processed. Messages placed onto the queue are stored until the consumer
retrieves them.

4. KEY CAPABILITIES
 Guaranteed message delivery
 Message prioritization
 Message backup and restore
 Sending messages to multiple destinations
 Cross-platform integration
 Message routing
 Dynamic queue creation
 Compatible with various transport protocols
 High-performance computing and high availability
 Asynchronous Communication

5. MQ - Simple Use Case / Purpose
 Let’s imagine that we’ve a web service that receives many requests every
second (i.e., Google), where no request is afford to get lost and all requests
needs to be processed by a process that is time consuming.
 Let’s suppose that our web service always has to be highly available and
ready to receive new request instead of being locked by the processing of
previous received requests. In this case it is ideal to put a queue between the
web service and the processing service.
 The web service can put the "start processing"-message on a queue and the
other process can take and handle messages in order. The two processes will
be decoupled from each other and does not need to wait for each other. If you
have a lot of requests coming in a short amount of time, the processing
system will be able to process them all anyway. The queue will persist
requests if their number becomes really huge.

6. Web Services vs. Message Queue (MQ)
Conditions Web Service Message Queue
If Server Fails: Client must take responsibility to handle the
error
Message Queue persist the message
(optionally, even if the machine shutdown)
If Server is working again: Client is responsible of resending it It receives the pending message
If Server gives a response to
the call & the client fails
Operation is lost If Client didn't acknowledge the response,
the message is persisted
Contention You don't have contention, i.e: if million of
clients call a web service on one server in a
second, most probably your server will go
down.
You have contention, you can decide how
many requests are handled by the server
Expect an immediate
response from the server
You can expect an immediate response from
the server, but you can handle asynchronous
calls too.
You don't expect an immediate synchronous
response, but you can implement/simulate
synchronous calls.

7. ActiveMQ Portal